A woolly mammoth that died millennia ago nursed for at least six years, according to an analysis of one of its tusks. The finding raises the question: Did its mother finally get tired of being poked?

“That’s an interesting question,” said Adam Rountrey, a graduate student in geology at the University of Michigan in Ann Arbor who helped analyze the tusk. “At this age the tusks are not protruding very far, but sure, eventually they could get in the way.”

If you think scorpions are scary, try this on for size: a six-legged water scorpion the size of a human. Newly discovered tracks reveal that about 330 million years ago, just such a creature lumbered along the riverbanks in present-day Scotland.

The fossilized track is the largest of its kind ever found and shows these now extinct creatures could walk on land, according to Martin Whyte, a geologist at the University of Sheffield in England.

The large, flightless moa bird that roamed New Zealand in ancient times grew much more slowly than modern birds, according to a new study of their bones. The finding suggests that slow growth doomed the moa to extinction when humans arrived about 700 years ago.

Unlike the bones of all modern birds, several moa bones show growth marks similar to the rings found on tree stumps, said Samuel Turvey, an ecologist at the Zoological Society of London in the U.K.

Robert Rohde and Richard Muller are vexed. For the past 542 million years the number of animal species living in the world’s oceans has risen and fallen in a repeating pattern, and the scientists haven’t the foggiest idea why.

“I wish I knew what it all meant,” said Muller, who is a professor of physics at the University of California, Berkeley.

Wild populations of Australian dingoes may go extinct within 50 years unless steps are taken to prevent crossbreeding with domestic dogs, scientists and conservationists say.

Like North American gray wolves, dingoes maintain strong social structures. Genetic evidence suggests Australian dingoes descended from a small group of ancient dogs—perhaps a single pregnant female—brought to Australia from Indonesia about 5,000 years ago.